Treatment of acidic dyes solutions by adsorption in soybean meal

In this study, we tested the potential use of a natural sorbent based on soybean meal from oil extraction in the treatment of solutions containing the acid dyes: yellow Erionyl RXL, navy blue Erionyl R and red Erionyl A-3B, used to dye polyamide fibers. To that end, adsorption studies were performed under different conditions of temperature, adsorbent concentrations, pH values, and color mixes (two-and three-color) on dye solutions produced in laboratory. Soybean meal showed great ability to remove color, especially in solutions with pH 4 and 6 at 60C and containing 10 g L -1 of adsorbent. Considering that values of adsorption efficiency ranged between 74 and 99%, depending on the dye and treatment conditions, soybean meal proved to be an alternative material for the adsorption of acidic dyes.